Work-driving dog.



S. W. PUTNAM. 3D.

v WORK DRIVING DOG.

APPLlcATloN FILED MAn.|8.1axa.

Patented lJuly 1l, 1916.

rwentO/z/ affonda SALMON WILDRrU'rNAr/r, si, FiaoHBUitiviAssAoiiUsE'rrs,,nsisonoatro E'iJiM PARK' PUTNAM', or rrrorinUnef, MAssnorr'usu'r'rs.

WORK-DRIVING nG Specication'of Letters Patent.

Application filed March 18, Serial No. 85,175.

T 0 all whom t may concern:

Be it known that I, SALMON W. PUT- NAM, 3d, a citizen ofthe United States, residing at Fitchburg, in the county of lVorcester and State of Massachusetts, have invented certain new and useful Improvements in lVork-Driving Dogs, of which the following is a specification'. l

My invention relates to certain new and useful improvements in driving-dogs particularly designed for use in'turning the steel tires of locomotive v driving-wheels, coachwheels, truck-wheels and all other wheels employinga'stee'l or other tire,the'turning being lperformed while the wheels are mounted upon their axles. Lathes of this type are well known, and it is'usual in performing the turning operation to mount the axle,I with its wheels, on thel centers .of` a double-head driving-wheel lathe, such lathes commonly presenting aface-plate contiguous tothe outer face of each drivingwheel when mounted upon the axle, as before men tioned. By suitable mechanism the two face plates are driven in unison.

kThe object of my invention is to equip such a .lathe as mentioned, or any other style of turning lathe, or dierent kinds of face-plates or table 'work on both the usual form of .so-called engine lathe, and boring or turning mills, etc., with a novel drivingdog which may be applied with little or no modification, to form a positive and effective driver which is equalizing, and capable of adjusting Iitself automatically to the load, or in other words to the resistance offered by the cutting tool.

W'ith the foregoing and other objects in view, my invention consists of the parts and the constructions and combinations of parts which Ijwill hereinafter describe and claim.

Inthe accompanying drawing forming.v

part of this specification and in which similar reference characters indicate like parts 1n the several views; Figure 1 1s a longitudinal sectionalview of a driving dog embodying my invention. -F ig. 2 is la front view of thesame. Fig. 3 is an'end view.

VThe driving dog which 1 am about to describe is designed primarily, as before stated, for use in `connection with steeltired-lathes and driving-wheel-lathes, and

which lathes 'usuallyl contain a head-stock and a: tail-'stock with face-plates between which the aXle with its wheels will eXtend, said head-stock andjtail-stoc'k being usually provided with internal spindle-,carrying centers having means of adjustment longi` tudinally, and` theI driving-dogs being usul ally adjustably secured in slots formed in the face-plates, but these features form' no part of theY present invention and hence are v'not illustrated.`

1n carrying'out myy present invention Y1 form the dog vo f a base-member' or jawholder, 10, having lugs, 11, through which pass bolts, 11,.by whichth'e jaw-holder is secured toand o utstands from the faceof the face-plate, the bolts being adapted yfor slidablefoperation in the usual radial'chani nels or slots formed in the face-,plate and being capable of adjustment radially from the' usual spindle-carrying" centers, and said jaw holder having a tongue, 10, which.' in actualvoperation, extends ,into'aT-slot' in the faceplate forminga means of positive driver and relieving the bolts which hold the driving-dog to the face-plate' of the lathe, from all drivingstrains.

. At the outer end, the jaw holder is channeled as at 12 to receive'and form a guide for the slidable serratedjaw, 13, the rearE wall of the channel in Awhich said jaw operates being inclined relatively to the'base portion, the said basey or rear of the sliding jaw beinginclined similarly to the Yinclined plane formed on the bottom or rear wall of the channel, 12, wherebythe jaw is accurately guided in its sliding movements.

The front face of the jaw is serrated or provided with teeth as is common in this type of dogs, said front or working face of thc jaw being preferably arranged at an angle to the inclined base or rear of said dog and substantially parallel with the faceplate of the lathe.

t vOne end of the channel, 12,V in which'th'e serrated jaw slidably operates, is closed byv a cover-plate, 14C, to which is secured by any suitable means, a guide rod, l5, and a spring, 16, encircling this rod passes into the bore or hole, 13, of the sliding jaw and is confined between the bottom of this bore and the inner face of the cover-plate, as shown in F ig. 1. One end of the jaw holder, 10', is also channeled in a plane substantially at right-angles to the base line of said holder and to the plane of the face-plate of the lathe and in this channel portion slidably operates a follower' or reaction block, 20,

I having a transverse projection, 21, which extends toward the adjacent edge of the slidable jaw, the face of said projection and the corresponding edge of the sliding jaw being similarly inclined for free sliding movement one on the other, and the body portion of the follower or reaction block being provided with a bore in which is contained a compression coiled spring, 22, the upper portion of which embraces a guide rod, 23, fixed to a plate, 24, which serves as a cover for the outer end of the channel, in which the block operates. The follower or block, 20, is also fixedly secured to or provided with a projecting finger-piece or handle, 25, which extends through a slot, 26,

formed in the adjacent wall of the jaw holder, 10, said finger-piece or handle having an opening, 27, through it and having a notch, 28, on its underside leading from said opening. The opening, 27, is adapted to admit a spring latch, 29, one end of which is secured in the jaw holder, 10, while the opposite end is free to work through said opening and to move outwardly and to spring into engagement with said notch, 28, when the finger-piece, 25, has been lifted high enough to allow for this operation.

In order that the present invention may be fully appreciated, it is well to here state that it has been noted under actual working conditions that theserrated sliding jaws of the prior art do not always assume a maximum high position on the inclined planes (dependent upon the magnitude of the cut), and remain there, but work back and forth in the holders on inclined planes, a condition presumably caused by the character of the material being machined, which in the case of steel-tired wheels is likely from the fact that many of them contain segregated hard spots quite frequently termed nigger heads. It will readily be understood then that the cutting tool when entering one of these hard spots is confronted with an instantaneous increased rethe sliding driving dog to rebound or slide downwardly and away from its maximum high position on the inclined plane, all of which makes for unsteady driving and causes vibration to occur in the machine, greatly reducing the efliciency of the latter. It is to preclude the possibility of this unsteady driving, due largely to backlash or rebound of the sliding driving jaw, that I have devised the present dog, the very nature of which might indicate it as being a non-reaction driving dog.

I/Vhile I have in the foregoing description identified the dog with a particular form of lathe, and as designed for a particular class of work, I wish it understood that I do not limit the invention to any special form of machine or character of work, neither do I limit said invention to the exact construction and arrangement of parts shown and described, as these are capable of material modifications, which will be within the scope of the invention substantially as,l hereinafter claimed. In other words, the present invention is believed to be broad enough to comprehend and include any and all means by which the foregoing defects in existing driving-dogs may be obviated, and all reaction or tendency of the dog to rebound or slide downward and away from its maximum high position on the inclined plane when the cutting tool is confronted with instantaneous increased resistance, is avoided. In actual practice one or more of these dogs would be mounted upon each face plate of the machine, the work placed in the lathe and the surface of the work to be driven brought into contact with the serrated driving surface of at least one driving' dog, the latch, 29, on the followerI or reaction member, 20, released and the lathe started up gither at this point or after the latches ofthe remaining followers or reaction members have been released, all according to convenience of operation and which in driving-wheel-lathe and coachwheel-lathe operation is usually after the lathe has been started up, as the face plate revolution is quite slow.

From the foregoing it will be evident that as resistance is encountered by the vcutting tool, the serrated sliding jaw slides up the inclined plane to a maximum height relative, of course, to the magnitude of the cut or resistance offered to the cutting tool, and the several serrated sliding jaws with which the lmachine will be provided, are automatically blocked against any backward sliding movement or rebound, from causes as previously described, by the constrained movements of the follower or reaction member, 20, said constrained movement being such that the inclined surfaces, a, and on the reaction member and contiguous edge of the sliding jaw respectively, always contact itY nie-151113' and thereby block the j awv against any'backward sliding motion or rebound, at the same time allowing the jawto'` readilyv assume still higher points on the inclinedplanes",l should greater resistance be encountered by the cutting tools and again become automatically blocked against backward sliding motion or rebound.

IVli'ile I have shown and-described acompression coiled spring, 16, actingv aga-inst the serrated sliding jaw, for the purpose of aiding in maintaining the surfaces, a and b, in a stateof coaction, this spring" is not essential for the successful operation of the driving-dog for ifv this coiled spring were omitted entirely, the co-acting surfaces, a and @could readilyr be dove-tailed each tothe other in a state of sliding contact and the action of the driving-dog remain unchanged; or, again, should the coiled spring be omitted entirely the serrated sliding jaw could be broughtv back by hand each time the follower or reaction member was latched at its highest point relative to the base line, X-Y, of Fig. l, and the action of the dog will still remain unchanged. l

The amount of backward sliding or rebound of the dogs, of the prior art seems to vary with the magnitudeof the angle of44 withV which angle the condition of backwardy slide or rebound was not so apparent but it soon became quite evident that this angle would have to be increased on account of end-thrust in machine and against wheels due to the action of this type of dog. When it is taken into consideration that the actual pressure developed on each cutting tool in machines of this class approaches 60 tons and that the end-thrust from driving-dogs is in round numbers represented by the product of this 60 tons multiplied by the cotangent of the inclined plane angle, it is at once apparent that the end-thrust was prohibitive and so intense was this end-thrust found to be under actual working conditions that wheels which had lbeen pressed onto axles by hydrostatic means would not hold their positions on the aXles against this end-thrust, but continued to slip or be pressed farther on the aXle, a condition which cannot be tolerated for one moment. Experiments were, therefore, made and it was found that while dogs constructed upon inclined plane angles as great as 25 degrees would grip with suficient intensity to drive the work against the cutting tools,` the condition of backlash or rebound in the serrated sliding jaws became verynoticeable and in some cases prohibitive as theeiii-` ciency of the machine was thereby greatly reduced.

Itwill'bev noticed, however, in the Ypresent illustration` that I am usingv an inclined plane angle of about 2:25` degrees and will likelyl adopt an even greater angle should experiment' seem to indicate such an action desirable. In the 22% degrees arrangement I have by virtue of the new'construction with reaction member precluded all` possibility of backward sliding or rebound of the serrated sliding jaw, and aty the same time I have reduced the former very dangerous and detrimental end-thrustto the irreducible minimum, which minimum will be at the greatest: angle of" incline plane a driving jaw1 will: gripv with suiiicient intensity againstthe work to properly drive the work against:v the cutting tool:

Having thus described lny'invention what I claim as new and desire to secure by Letters'Patent iss.

l. The combination with the sliding jaw of a driving-dog, of means engaging therewith lfor substantially continuously blocking the jaw against backward motion or rebound.

2. A driving-dog having a slidablymounted'jaw, and means movable in unison with the jaw and engaging said jaw and automatically blocking the same against rebound or return movement.

3." A driving-dog having a movablymounted jaw adapted to automatically adjust itself 1n response to an increased resistance toa cutting tool, said dog having meansmovable in unison with and engaghaving' a slidably-mounted gripping jaw constrained to move in a path oblique to the direction of movement of the dog, of a follower engageable with and responding to the movementof the jaw and blocking the rebound or return movement thereof.

6. The combination with a driving-dog having a gripping jaw constrained to move in a path oblique to the direction of movement of the dog, of a slidable block following the sliding movement of the jaw and adapted Vto block the rebound or return movement of saidjaw.

7. The combination with a driving-dog having a gripping' jaw constrained to move in a path oblique to the'direction of movement of the dog, of a slidable block following the sliding movement of the Vjaw and adapted to block the rebound or return IIO movement of said jaw, and a latch for holding the block at the outer limit of its movement.

8. The combination with a driving-dog having a gripping jaw constrained to move in a path oblique to the direction of movement of the dog, of a slidable block following the sliding movement of the jaw and adapted to block the rebound or return movement of said jaw, a, latch for holding the block at the outer limit of its movement, and a compression spring confined between the block and a fixed part of the dog, and operating eXpansively against the block.

9. The combination with a driving dog having a jaw-holder and a jaw slidably mounted in the holder and movable in a path oblique to the direction of movement of the dog, of a. follower backing up the j aw in its gripping nio-vement and blocking a rebound or return movement of said jaw.

10. The combination with a driving dog having a gripping jaw constrained to move in a path oblique to the direction of movement of the dog, of a slidable block following the sliding movement of the jaw and adapted to block the rebound or return movement of said jaw, said jaw and follower having similarly inclined slidably engaged surfaces.

11. A movable work ldriver comprising a jaw mounted to slide in a path oblique to the direction of movement of the dog, and propelling means for holding the jaw retracted out of engagement with the work but maintaining the jaw free to advance to a higher inclined 1position in response to increased resistance offered a cutting tool, and means engaging the jaw and continuously blocking the same against rebound or retrograde movement. n

12. A movable work driver comprising a jaw mounted to slide in a path oblique to the direction of movement of the dog, and propelling means for holding the jaw retracted out of engagement with the work but maintaining the jaw free to advance to a higher inclined position in response to increased resistance offered a cutting tool, and a follower backing against the jaw and holding said j aw in its advanced position against rebound or retrograde movement.

13. A movable work-driver comprising a jaw-holder and Va jaw mounted to slide therein in a path oblique to the direction of movement of the dog, and a propelled follower maintained in contact with the jaw and adapted to advance the same when latent to progressively increasing elevations along its path of movement, and maintaining the jaw blocked against rebound or retrograde movement.

144.. A movable work-driver comprising a jaw-holder and a jaw mounted to slide therein in a path oblique to the direction of movement of the dog, and a propelled follower maintained in contact with the jaw and adapted to advance the same when latent to progressively increasing elevations along its path of movement, and maintaining the jaw blocked against rebound or retrograde movement, said j aw and follower having opposed inclined surfaces maintained in slidable contact.

15. A movable work-driver comprising a jaw-holder and a jaw mounted to slide therein in a path oblique to the direction of movementA of the dog, a propelled follower maintained in contact with the aw and adapted to advance the same when latent to progressively increasing elevations along its path 4of movement, and maintaining the aw blocked against rebound or retrograde movement, said j aw and follower having opposed inclined surfaces maintained in slidable contact, and latching means for holding the follower in a retracted position.

16. A movable work-driver comprising a jaw-holder and a jaw mounted to slide therein in a path oblique to the direction of movement of the dog, a propelled follower maintained in contact with the jaw and adapted to advance the same to progressively increasing elevations along its path of movement, and maintaining the jaw blocked against rebound or retrograde movement, said jaw and follower having opposed inclined surfaces maintained in slidable contact, a latch for holding the follower in a retracted position, and a compression spring for advancing the follower and in turn moving the aw along its oblique path, when the latch is released.

17. A movable work-driver comprising a j aw-holder having a guide arranged oblique to the direction of movement of the dog; a serrated jaw slidably mounted on said guide and having an inclined edge; a follower block mounted to slide in the holder in a plane substantially parallel with the aXis of the work, and backing against the jaw and having a projection with an inclined face contacting with the inclined edge of the j aw; a compression spring engaged by the block; and a latch for detachably holding the block retracted and with said spring under compression.

In testimony whereof l affix my signature.

Y SALMON winnen PUTNAM, 3D.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

